US2368007A

US2368007A - Method of finishing bearing cups

Info

Publication number: US2368007A
Application number: US379048A
Authority: US
Inventors: Edward H Delahan; Albin G Frojd
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1941-02-15
Filing date: 1941-02-15
Publication date: 1945-01-23
Anticipated expiration: 1962-01-23

Description

Jan. 23, 1945. DELAHAN ETAL 2,368,007

METHOD OF FINISHING BEARING CUPS Filed Feb. 15, 1941 fill/6 7150715 Patented Jan. 23, 1945 UNITED STATES PATENT METHOD O INIsm eI nEARrnGo rs Edward H. Delahan and AlbinlG. Frojd,.Rockford, s rs to e-:Warn, Corpora on. .Chicago,.1ll., a corporation of Illinois Application February 15, lllal serial No. 37?,948

3 I Claims.

This invention relates to the manufacture of bearing cups for universal joints, of the type wherein a bearing cup is secured againspradial escape under centrifugal force, ,in acylindrical socket of a yoke member, by an annular securing element engaging against a seat formed in the periphery of the bearing .cup.

The general purpose of the invention is ,to provide an improved method of finishingsuch a bearing cup so as to maintain a very accurate uniformity of tolerance in the spacing between the seat and the inner surface of the end wall after the bearing surfaceshave beenhardened,

thereby eliminating the distorting effect'ofthe hardening step on the spacing between the seat and the inner end bearingsurface, and yet permitting the use of a shavin tool .for performing the seat facing operation ina rapid manner.

A further object of the invention is to provide a novel and improved apparatus for facin the securing element seat.

Other objects, the advantages and uses of the invention will become more apparent after reading the following specification and claims, and after consideration of the drawing forming a part of the specification, wherein:

Fig. 1 is an axial sectional View of a bearin cup in the form of a work piece formed to rough dimensions;

Fig. 2 is a view illustrating the plating of the work iece;

Fig. 3 is a view illustrating the plated work piece;

Fig. 4 is a view schematically illustrating the carburizing of the work piece to harden the interior 0f the cup;

Fig. 5' is a view illustrating the finishing ofthe interior surface of the cup; Fig. 6 is a view illustrating the final step 0 shaving the snap ring seat; and

Fig. 7 is an enlarged detailed view illustrating the same step. I

Our improved method of finishing a universal joint bearing cup embodies the following steps: 1. The bearing cup (indicated generally at 8) is fabricated to rough dimensions, in any suitab mann a b t m e rom kbi by drawing or coining from heavy sheet metal.

The cup 8 thus fabricated will be substantially as sh wn i s ci p i 1; n ud n a r mdrical lateral wall l0 and a fia't end wall "H.

During the turning operation, if employed, the

groove l2 which receive'sthe securing element which maybe in the form of an annular spring clip, commonly designated a sn'ap ring) ,{is rough turned in the exterionof the wall 10f 2. The mouth of'th' cup is' then closed with a rack, and the rack is dipped in'to' asolution which deposits copper plating M on the exterior surface'of the walls l0'andfl l,leaving the' ihterior surfaces thereof unplated, or the cups may be placed-in a wire basket and thus dipped in the plating solution. "3. The'-cups are then removedfrom the rack and the plugs are taken out.

4. The cups are then subjected to a suitable carburizing" process in which the interior surfaces of the walls 1-0 and H are carburized as indicated a1; l-9 while the exterior surfaces there of remain unafiected due to-the-protective coat- :ing of copper.

5. Immediately after removingi-fromrthe Icarthe cups are 6. The cup is then subjected to a finishing operation in which the. interior" and exterior cylindrical surfaces of the walls lll are ground accurately by means of a grinding wheel l8 to finished dimensions, and the interior surface of the end wall H is lapped to its finished state. During this finishing operation, the copper plating is removed from the exterior of the walls I0 and II.

7. The bearing cup is then inserted in the machine in which the last step of the method is carried out, this step comprising the facing of the snap ring seat [6 in the groove l2 by means of a shaving tool 20 (see Fig. 6) while the inner surface of the end wall H is main tained in locating contact with the end of a chuck I! on which the bearing cup is mounted during this facing operation. Since the inner surface of the end wall H has previously been accurately finished, the finishing of the snap ring seat to a close tolerance in dimension between the seat and the inner surface of the end wall H depends upon the position of the tool 20 with which the facing is done, relative to said inner surface.

8. After a predetermined number of bearing cups have thus been finished, one of the finished cups is measured to determine the amount of deviation from the specified dimension between the seat and end wall II, and the tool I4 is adjusted an amount sufficient t compensate for said deviation. Such testing and adjustment is performed periodically during the operation of the machine, and is necessary to compensate for tool wear.

Referring to Fig. 6, there has been indicated in dotted lines the position that the bearing cup will bear to a universal joint yoke lBa when installed therein including the manner in which the snap ring l6b cooperates with annular seat IS. The journal of the universal joint is not shown but will assume a position corresponding to that of the chuck H. It will thus appear that the dimension 3 indicating the distance between the side wall of annular seat IB remote from the inner end of the bearingcup and the inner end of the bearing cup must be maintained to a close tolerance.

Our improved method makes it possible to face the seat l6 by a shaving operation, which is much faster and less expensive than the grinding operation. If the seat is to be faced in hardened material, a grinding operation is necessary. If the seat is faced prior to the hardening operation, the latter will distort the dimension between the seat and the inner end surface of the cup. Extreme accuracy in the dimension X between the inner surface of the end wall and the seat I6 is obtained by leaving the exterior of the cup unhardened and performing the seat facing step as a final operation after the cup has been hardened and the inner surface thereof finished by grinding, the'cup being located against the end of the chuck I! so as to determine the dimension X.

We claim:

1, The method of fabricating universal joint bearing cups having an annular seat formed in the external surface thereof adapted for cooperation with a snap ring securing element, it being important that extreme accuracy be maintained in the spacing of the inner terminal surface of said cup with reference to the wall of said annular seat, said method including the steps of forming a cup-shaped bearing with a snap ring groove therein, plugging the mouth of said cup for protecting the interior surfaces thereof reference to the inner terminal surface of the bearing cup.

2. The method of fabricating a universal joint bearing cup having an external annular groove formed therein for the reception of a securing snap ring element and in which extreme accuracy is required between the inner terminal surface of said cup and the seating surface for said snap ring, said method including the steps of forming the cup to rough dimensions with a snap ring groove in the outer periphery thereof, providing the interior of the cup with a hardened bearing surface including a hardened inner terminal surface, while leaving the exterior of the cup unhardened, subsequently positioning said cup with reference to said inner hardened terminal surface thereof, machining the snap ring seating surface of said annular groove to give the same a selected precise spaced location with reference to said inner terminal locating surface whereby the snap ring when positioned within said annular seating surface in contact with the associated supporting yoke will be effective to confine said cup properly with reference thereto.

3. The method of fabricating a universal joint bearing cup having an external annular snap ring receiving seat therein, said method including the steps of forming a. cup-shaped bearing with a snap ring groove, plugging, plating, removing the plug and carburizing the interior of said cup, simultaneously finish machining the inner and outer cylindrical surfaces of said cup and the inner terminal portion to final shape, to provide said inner terminal surface as a locating surface, locating the inner cylindrical and inner terminal surface accurately in relation to the snap ring groove and shaving the snap ring seat portion to an accurately spaced relationship with reference to the inner terminal surface of the bearing cup.

EDWARD H. DELAHAN. ALBIN G. FROJD.